This invention relates to a method and system for ion beam milling a glass substrate prior to depositing a coating system (e.g., diamond-like carbon (DLC) inclusive coating system) thereon.
Each of the aforesaid parent applications relates to a DLC inclusive coating system on a substrate. Certain embodiments of certain of the parent applications relate to hydrophobic DLC inclusive coating systems where it is desirable to deposit a coating system having a high initial contact angle xcex8.
Each of the coating systems disclosed in the aforesaid parent applications is excellent and works in an efficient manner. However, the coating systems may be improved by increasing their adherence to the underlying substrate. Moreover, it would also be beneficial to increase the scratch resistance of such coating systems.
Thus, it will be appreciated by those skilled in the art that there exists a need(s) in the art for a method of manufacturing any of the coating systems in the aforesaid parent applications (or any other suitable coating system) in a manner so as to improve adherence to the underlying substrate and/or to make the resulting coated article more scratch resistant. It is a purpose of different embodiments of this invention to fulfill one or more of the above described needs in the art, and/or other needs which will become apparent to the skilled artisan once given the following disclosure.
According to exemplary embodiments of this invention, a glass substrate is ion beam milled prior to deposition of a coating system (e.g., diamond-like carbon (DLC) inclusive coating system) thereon. Ion beam milling functions to remove or shave off a portion of the glass substrate in order to smoothen a surface of the substrate and/or remove/reduce nano-cracks which may have been present in the original substrate surface. Following the ion beam milling, the coating system is deposited on the smoothened surface of the substrate (e.g., via ion beam deposition, sputtering or the like).
According to certain exemplary embodiments of this invention, ion beam milling of a substrate prior to deposition of a coating system thereon enables resulting coating systems when deposited to better adhere to the substrate. Moreover, with respect to DLC inclusive coating systems, it has surprisingly been found that such ion beam milling results in the coated article having improved scratch resistance. Ion beam milling may also function to reduce sodium (Na) content adjacent a milled surface of a soda inclusive glass substrate (e.g., soda-lime-silica glass substrate), thereby reducing the potential for sodium induced corrosion on the resulting coated article.
Coated articles made according to certain embodiments of this invention may be hydrophobic (e.g., shed water) or non-hydrophobic in different embodiments. In hydrophobic embodiments, an object of this invention is to provide a durable coated article that can shed or repel water (e.g. automotive windshield, automotive backlite, automotive side window, architectural window, bathroom shower glass, residential window, bathroom shower door, coated ceramic article/tile, etc.).
The hydrophobic nature of such articles is often characterized by relatively high initial contact angles xcex8. For example, coated articles herein may be characterized by an initial contact angle xcex8 (i.e. prior to being exposed to environmental tests, rubbing tests, acid tests, UV tests, or the like) of at least about 55 degrees, more preferably of at least about 80 degrees, even more preferably of at least about 100 degrees and most preferably of at least about 110 degrees.
The instant ion beam milling invention may be used in conjunction with various types of DLC inclusive layer systems and other types of coating/layer systems, and is not intended to be limiting in that regard.
Generally speaking, certain exemplary embodiments of this invention seek to fulfill one or more of the above-listed needs in the art by providing a method of making a coated article comprising the steps of:
providing a substrate;
ion beam milling substantially an entire surface of the substrate so as to thin the substrate and smoothen the surface of the substrate; and
depositing a coating system on at least a portion of the ion beam milled surface of the substrate following said ion beam milling step so as to form the coated article.
In certain embodiments, the method of claim 27, wherein said ion beam milling step is performed in a manner so as to increase scratch resistance (SR) of the coated article by at least a factor of two, and/or so that an average surface roughness of the ion beam milled surface of the substrate following said ion beam milling is no more than about 80% of what an average surface roughness of the surface of the substrate was prior to said ion beam milling.
In certain embodiments, the depositing step comprises ion beam depositing at least one DLC inclusive layer on the ion beam milled surface of the substrate.
Certain exemplary embodiments of this invention further fulfill one or more of the above-listed needs by providing a coated article comprising:
an ion beam milled glass substrate; and
a coating system including at least one layer deposited on an ion beam milled surface of said glass substrate.
This invention will now be described with respect to certain embodiments thereof, along with reference to the accompanying illustrations.